Ice disrupting apparatus for an electric scissors type switch



March 24, 1970 H. FRIEBE ET AL 3,502,826

ICE DISRUPTING APPARATUS FOR AN ELECTRIC SCISSORS TYPE SWITCH Filed Feb. 14. 1968 Fig. 1

United States Patent 3,502,826 ICE DISRUPTING APPARATUS FOR AN ELECTRIC SCISSORS TYPE SWITCH Harry Friebe, Winfried Oltersdorf, and Karl-Heinz Picard,

Berlin, Germany, assignors to Siemens Aktiengesellschat't, a corporation of Germany Filed Feb. 14, 1968, Ser. No. 705,348 Claims priority, application Germany, Feb. 24, 1967, S 108,486 Int. Cl. H01h 31/02 US. Cl. 200-48 8 Claims ABSTRACT OF THE DISCLOSURE A hood of substantially U-shaped configuration covers one of a plurality of mutually coupled parts of an electric scissors type switch at a determined distance from such part. The parts of the switch are movable relative to each other. The hood is supported for limited movement relative to the part which it covers by a plurality of springs.

Since the switches must be maintained in operable condition at all times, they are usually provided with very strong actuating or driving power. The driving or actuating power is so strong that the switches may be made operable by moving their movable parts although they are covered by a sheet of ice as thick as 1 cm.

'The considerable actuating force or power is a disadvantageous solution to the icing problem, since it creates further complications, especially in disconnect or cut-off switches. This is especially the case in a scissors or tong type switch in which the movable contact or switching parts are in a scissors type relation with mutually coupled parts which are movable relative to each other. In the conductive or ON condition or position of the switch, the ice may prevent movement of the movable parts to the extent that extremely great actuating power is required to switch to the non-conductive or OFF condition or position. After the ice has been disrupted or broken up, the considerable actuating power switches the switch at undesirably high speed and subjects the switch to very high mechanical stresses due to impact, and the like.

The principal object of the present invention is to provide a new and improved ice disrupting apparatus for an electric switch.

An object of the present invention is to provide ice disrupting apparatus for an electric switch which is of simple structure and does not require the utilization of high actuating power for the operation of the switch.

An object of the present invention is to provide ice disrupting apparatus for an electric switch which permits a reduction in actuating power for switching due to the successive disruption during the switching operation of ice formed on such switch.

Another object of the present invention is to provide ice disrupting apparatus for an electric switch which functions with efficiency, etfectiveness and reliability to disrupt ice formed and forming on the movable parts of the switch.

In accordance with our invention, ice disrupting apparatus for an electric switch comprises a hood covering one of a plurality of mutually coupled parts of the switch movable relative to each other and subject to icing. The hood covers the one of the parts at a determined distance therefrom. A support supports the hood for limited movement relative to the one of the parts.

The support comprises a plurality of spaced helical springs each having one end afiixed to the one of the parts and the other end aflixed to the hood. The hood comprises a metal sheet of U-shaped configuration having spaced leg portions and a head portion joining the leg portions. The leg portions of the hood extend over the sides of the one of the parts and the head portion of the hood extends over the top of the one of the parts.

The switch is a scissors type disconnect switch including a crank part movable relative to the other parts thereof and the hood covers the crank part. A plurality of spaced helical springs each has one end afiixed to a side of the crank part and the other end affixed to a leg portion of the hood. The crank part is positioned substantially horizontally.

In order that the present invention may be readily carried into effect, it will now be described with reference to the accompanying drawing, wherein:

FIG. 1 is a view of part of a scissors type disconnect or cut-oif switch including an embodiment of the ice disrupting apparatus of our invention;

FIG. 2 is a top view of the ice disrupting apparatus of FIG. 1, on an enlarged scale; and

FIG. 3 is an end view of the ice disruptingapparatus of FIGS. 1 and 2.

In FIG. 1, a support insulator 1 supports the gear housing of an outdoor high voltage scissors or tong type disconnect or cut-01f electric switch. A pair of scissors or tong arms 5 and 6 are pivotally mounted in a gear housing 2 by pivots 3 and 4, respectively. The scissors arms 5 and 6 of the switch function as the movable contact or switching members.

In the conductive or ON condition of the switch, the arms 5 and 6 cooperate with counter-connected contacts (not shown in the figures). A first coupling member 9 is coupled at one end to one end of a crank part 11 of the switch and is coupled at the other end to the arm 5. A second coupling member 10 is coupled at one end to the other end of the crank part 11 and is coupled at its other end to the arm 6. The crank part or crank 11 is pivotally mounted in the gear housing 2 by a pivot 12. The crank 11 is moved or rotated by a gear positioned in the gear housing 2 (and not shown in the figures). The gear is coupled to a suitable driving device such as, for example, a hydraulic pneumatic or motor drive (not shown in the figures), via an insulated drive shaft 13.

As shown in FIG. 1, the scissors arms 5 and 6, the coupling members 9 and 10, the crank 11, the gear housing 2 and the insulated drive shaft 13 are mutually coupled parts of the control switch which are movable relative to each other. These parts are subject to icing, in which condition they may become affixed to each other via ice. The parts of the switch are moved relative to each other during the switching operation. If ice coats the equipment, it must be broken up or disrupted to permit proper operation of the switch.

In accordance with our invention, a hood, cover, dome, or the like, 15 is provided to disrupt ice formed or forming on the movable parts of the switch. The hood 15 is positioned on and over the substantially horizontally disposed crank 11, so that said hood covers said crank. The hood 15 covers the crank 11 at a determined distance from said crank and is supported by said crank for limited movement relative thereto. The hood 15 comprises a metal sheet of U-shaped configuration having spaced leg portions 16 and 17 and a head portion joining the leg portions. The leg portions 16 and 17 of the hood 15 extend over the sides of the crank 11 and the head portion of said hood extends over the top of said crank, so that said crank is covered or housed against the elements. Only negligible icing may occur between the hood 15 and the gear housing 2. Furthermore, the hood 15 functions as a shield between the crank 11 and the coupling members 9 and 10.

The hood 15 insures the movement, to a determined extent and without notable difficulty, of the moving parts of the switch covered thereby. During such movement, the ice coating the other parts which are coupled with the moving part, and which are not covered, is disrupted or broken up. The hood 15 is incrementally moved by the part or crank 11 which it covers, so that the ice is incrementally disrupted in the area of the hood.

Under certain circumstances, a plurality of hoods may be utilized, in accordance with the thickness of the ice coating the equipment or in accordance with the dimensions of the most vulnerable parts. The ice is then disnlpted or broken up in more than two steps such as, for example, 4, 6 or more steps, in accordance with the number of hoods utilized in the individual localities. As a result, the actuating or operating power or driving force can always be reduced to a magnitude which is only slightly greater than that required to operate the switch when it is free from ice.

The shape of the hood 15 need only generally follow the contour of the movable part which it covers. It is important only that the ice be prevented from forming in places between the movable parts and be permitted to form only between the hood 15 and the adjacent parts, so that the movable parts of the switch are permitted to perform a limited switching movement at the covered locality until they abut said hood. Different hood shapes may be utilized, dependent upon whether the covered part moves longitudinally, rotatably, oscillatorily or pivotally. For a moving part such as, for example, the crank 11, which is substantially horizontal in position, a hood 15 of substantially U-shaped configuration, as hereinbefore described, is suitable.

The hood 15 is supported by four helical springs 18. A greater number of springs may be utilized, if desired. Each of the helical springs 18 is afiixed at one end to a corresponding side of the crank 11 and is affixed at the other end to a corresponding leg 16 or 17 of the hood 15. The springs 18 permit limited movement of the crank 11 within the hood 15; the hood being assumed to be stationary. Only after it moves from 1 to 2 cm., for example, measured at its ends, does the crank 11 abut the hood 15. Further movement of the crank 11 then moves the hood 15 alng with said crank.

The springs 18 permit the hood 15 to be directly affixed to the part which it covers. Since the springs 18 are preferably afiixed to the hood 15, they may be mounted with facility, together with said hood, during assembly of the equipment. This also provides considerable simplicity and facility in installing the hood 15 only on those switches which are subjected to icing. Other switches, which will not be subjected to icing such as, for example, those to be utilized in the tropics, are not fitted with the hood 15.

When the switch is in its condition or position illustrated in FIG. 1, and ice is forming or has formed thereon, such ice forms on the hood 15 and in the area or vicinity of the crank 11. The ice affixes the hood 15 to the gear housing 2, since it forms a solid sheet of ice therebetween. The ice may also affix the hood 15 to the coupling members 9 and 10, since it also forms a solid sheet of ice between said hood and said coupling members. The ice formed between the crank 11 and the gear housing 2, as well as the ice formed between the coupling members 9 and 10, is slight in contrast with the aforedescribed solid sheets of ice.

Due to the relatively slight covering of ice between the crank 11 and the gear housing 2 and between the coupling members 9 and 10, the crank 11 may be initially turned without creating any considerable stress. The sheet of ice at the coupling members 9 and 10 and at the scissors arms 5 and 6 is thus disrupted or broken up at the commencement of the disconnecting movement of the switch parts. Considerable actuating or operating power is available for the commencement of the disconnecting movement of the switch parts, since the heavy icing between the hood 15 and the gear housing 2 remains intact at that time. After the ice between the scissors arms 5 and 6 and between the coupling members 9 and 10 has been disrupted or broken up, however, the crank 11, in its movement, reaches and abuts the hood 15 during the continued disconnecting movement of the switch parts. When the crank 11 abuts the legs 16 and 17 of the hood 15, it disrupts and breaks up the ice between said hood and the gear housing 2. Almost the entire actuating, operating or driving power or force is available for the purpose of disrupting the ice between the hood 15 and the gear housing 2, because the ice at the scissors arms 5 and 6 and coupling members 9 and 10 has already been disrupted or broken up. The scissors type switch of our invention thus provides a disconnecting operation energized by very small actuating or operating power.

The hood or hoods of our invention may be utilized with any switch which requires an incremental disruption or break-up of a covering of ice on its movable parts. The hood or hoods operate to disrupt or break up the ice in the aforedescribed manner.

While the invention has been described by means of a specific example and in a specific embodiment, we do not wish to be limited thereto, for obvious modifications will occur to those skilled in the art without departing from the spirit and scope of the invention.

We claim:

1. Ice disrupting apparatus for an electric switch having a plurality of mutually coupled parts movable relative to each other and subject to icing, said apparatus comprising hood means covering one of said parts at a determined distance from said one of said parts; and a plurality of springs supporting said hood means for limited movement relative to said one of said parts.

2. Ice disrupting apparatus as claimed in claim 1, wherein each of said plurality of springs has one end affixed to said one of said parts and the other end afiixed to said hood means.

3. Ice disrupting apparatus as claimed in claim 1, wherein each of said plurality of springs is a helical spring having one end affixed to said one of said parts and the other end affixed to said hood means, said springs being spaced from each other.

4. Ice disrupting apparatus as claimed .in claim 1, wherein said hood means comprises a metal sheet of U- shaped configuration having spaced leg portions and a head portion joining said leg portions, the leg portions of said hood means extending over the sides of said one of said parts and the head portions of said hood means extending over the top of said one of said parts.

5. Ice disrupting apparatus as claimed in claim 4, wherein each of said plurality of springs is a helical spring having one end aifixed to said one of said parts and the other end afiixed to a leg portion of said hood means, said springs being spaced from each other.

6. Ice disrupting apparatus as claimed in claim 4, wherein said electric switch is a scissors type disconnect switch including a crank part movable relative to other parts thereof, and wherein said hood means cover said crank part.

7. Ice disrupting apparatus as claimed in claim 6, wherein each of said plurality of springs is a helical spring having one end aflixed to a side of said crank part and the other end affixed to a leg portion of said hood means, said springs being spaced from each other.

8. Ice disrupting apparatus as claimed in claim 7, wherein said crank part is positioned substantially horizontally.

References Cited UNITED STATES PATENTS 4/ 1957 Harault.

6/1966 Curtis et al 20048 

